quill stems

[graeme]

Ive got a GT piston stem on my rider and i cant get it tight enough.

It moves every time im out riding, im not riding it hard, just dropping the bike seems to be enough to move it round.

Its not the shaft moving in the block as i marked them both so i can keep an eye on that.

I work on cars so im used to doing things up tight but this just doesnt want to hold. I can probably get it tighter but i dont want to strip the threads. Im using about 12" of leverage and doing it up damm tight.

Any other reasons why it may not tighten? Theres no bulges in the fork tube.

If not, ill just wrench it as hard as i can and if it strips, so be it.

[graeme]

The grip to the bars is fine, its turning in the forks

[graeme]

I might take it over the workshop and put the air ratchet on the fooker 

[moley]

try using a shim, your bars might be ovalised

I think he's saying its turning not the bars going forward or backward!!

Take your quill out and give it a good clean down the forks.   Maybe there is a load of loose dirt or rust down there that the quill can't tighten up on.

Also check the quill.   Some quill ends were smooth and some had ridges so it could bite the inside of the forks.   If its smooth then it wont help grip the stem.

Have you got another stem to try in it!!  Any stem will do, just to check that its the stem at fault and not your forks!!!

Also if someone has over tightened a stem in those forks then it might leave an impression of the old quill inside the forks.  When you try tightening your quill it might be making minimal contact inside the forks so that there is some play left and right but the quill cannot be pulled out.

Thats it, I'm all out of suggestions!!  

[Mattdub]

Try an alternative wedge 

[graeme]

No alternative parts to try, the wedge is ridged.

Ill try cleaning everything up, check everything over and try again.

[graeme]

took it out and cleaned everythign up. Was a little dirty but not much.

The ridged wedge is to blame i think, you can see where its shiny where its been touching the fork tube, and its only 1 or 2 spots. Its not making proper contact.

I dressed it a little with a file but ill put a new wedge in it when i can.

Thanks.